Simply put, some problems with 3e and 4e run so deep just "houserules" can't fix them. The Fighter/Wizard problem. Multiclassing. Terrible feats. A broken RNG with skills. Magic items being terrible. Simply put, I do intend to work at a "system" level to a large degree. But I don't intend to do some radical new system with bizarre dice rolling that will tottally bring RPGs into a new era or whatever. I intend to make a fantasy RPG that is familiar, and "just works". Really, it's like what Sirlin says about Starcraft 2 or whatever, about how just taking what is there and improving, polishing, and taking what you've learned. I'm about to go in on equipment, magical items, and monsters (hopefully) this weekend, showing how I DO hope to innovate there, at least. Also, I think it's important to know "where you're going" so to speak. Your combat rules are not the place to start. You need to describe who the PCs are, what they'll be doing, what players have to interact with, etc. Sketch out what the system will look like without the details, and THEN fill those details in. That's kind of what I'm doing first - going over a theoretical "player's handbook" chapter by chapter, putting more in each time. Also, d100 systems are neat, and can have a lot of awesome effects when it comes to stuff like crits and special abilities. However, I am going for KISS with this system, and never plan on handing out %s that are different from 5% or a multiple thereof, so a d20 is basically just a d100.